Coil-supporting structure



Nov. 16, 1948. o. l. PRICE COIL-SUPPORTING STRUCTURE Filed Feb. 14, 194s A fr0/wmp @y my PJ Ef! El Patented Nov. 16, 1948 GEEL-SUPPORTING STRUCTURE Osbornczl. Price,A Frederick, Md., assigner-t0 Mag-f netic- Devices, Inc-.,.Frederickg' Mdr, a corpora.-

tion of Maryland.

Application February-14, 1946,4 Serial-No. 647.34541 12.(3laims. (Cl.-..175.-2.l)

l My invention relates broadly to electromagneticf-devicesfand'more'particularly to a coil supporting structure for electromagnetic devices.

One of. the. objects of my' invention is-to provide` anv improvedf arrangement of coil supporting structure for facilitatingma-ss production of electromagnetic devices at minimumyrcost:

Another object of-my'sinvention is'to provide a' constructionof insulatedspool head Jfor electromagnetic devices havingY terminal members for thefcoilwinding moldedl directlyA into-the insulation material of the spool head.

Still another object offv my invention is toY provide a-construction of spool-support forl electromagnetic windings embodying both an insulation head-and arr adjacentmeta'llic reinforcing-'head in-whichthe metallic-'reinforcing head may be formed to electrically control apatlr for eddyy currents immediately adjacent' the field'of'the. electromagnetic Winding carried b'y ythe spool support;

A` further object of my invention iste-provide means for keying a-spool. head ofinsulation material with a reinforcing head -of metallic mate'- ria-lwherein the head of insulation material servesto support terminal lugsy in a positionfor establishing` electric connection with an electromagnetic Winding'carried -by theassociated` :spooll Still another ohjectofI my invention ist to provldea construction of'insulatedhea'dt for electromagnetic -bobbins having 'means molded into the head for `starting the Windingon'thev bobbin in4 ing lay-reference -to the accompanying drawings in which:

Figure 1 is a side elevational view-illustrating the assembly of the-bobbin support-including the spoolheads of myinvention; Fig. 2.is,an end view of the bobbinshown*` in Figure 1 loolring in the-directionof arrow- A; Fig... 3I is an. end viewof the electromagnetic bobbin looking inY the directionof arrow B. of Figure 1; Fig. 4 is an enlarged transverse sectional viewtaken online 4-4of Fig. l; Fig.- 5-is a fragmentary side elevational view ony anl enlarged scaleshowing the composite spool headY of l insulationandI metallic material with the terminallugs fora the electromagnetic Winding extendingr therefrom; Fig; 6

is a vertical sectional .View takenonlinefG-Qoi Fig. 4'; Fig. 7. is a transverse sectional view taken 2- on--line T T of Fig. 4; Fig. 8 is a view similar to the view-shown inyFig, 7- after the. coilwinding is; inplace and showing the layer of insulation material provided for substantially sealingv the;

- conductor constituting ythe electromagnetic -Windning in' position; Fig.. 9 Sis a fragmentary sectional view of: afportion ot thecompleted-1 electron'lag-` netic :winding illustrated iadjacent the' spool yhead construction otmy: invention; Fig. 10 is--an ele'- vational view of a metallic insert for the spool head constituting a.- completely closed eddy; current-ringinlthe field of electromagnetic'W-inding;

1,1 is-avertical.'sectional` view taken-on linez tlf-Hof Eig.- 10.; Eig .-.12-is an elevationalfviewv of the metallic insert for-the insulated` spool head slotted :to reduce the-conductive .path ofV the :mestallic spool head foreddy current; Fig. 13'is aI verticalsectionalview on line l3-I3.-of Fig. 12; Fig. 14 is an elevational-.view of ,another modified form of metallicl spool head having an end slot therein for controllingan eddy currentpath ad"- jacentthe magnetic Winding; Fig. 15 is a vertical sectional v ieW- on line- #5a-I5- oi Fig. 14'; Fig. I6 is an elevational viewfoi a further modiedfform' of metallic spoolhead slotted for interrupting` the eddy current path adjacent theA electromagnetic Winding, and Fig, 1.7- is-avertical sectional View taken on line H-ll.- of Fig. 16.

Referringf'to the drawingsv in detail, the magnetic core for the-electromagnetic device-oi my invention -is-represented'lby reference character l, having annularffla-ngedhead! thereon vat-one end and having a screw threaded recess-3 in the opposite endHthereof-forfthe entryof a-screw member servingto support the core. Immediately adjacent1 the abutment provided by the annular iiange 2 onmagnetic core-l, I position the metallic head 6;. The metallic head` 4 is constructed in a varietyv oi forms to regulate the amplitude of the eddy currents which may be set up in the metallic head. Themetallic head is' formed'from nonmagnetic material, generally of brass Which may be nickel plated. As-shoW-nfin Fig. 2 the metallic head d is slotted at E'Which'restricts the eddy current path and tendsto slowdownthe opera tionof' the electromagnetic device oy-controlling the-counteraction. of the magnetic fielddeveloped-fromthezeddy current with respect to the magnetic iield oi?` the' magnetic winding carried by the boh-bin vof the electromagnetic device. The slot Salso serves as a centering and keying 'means between the metallic head' ll V and-the insulation head S. For electromagnetic devices having a magnetic core-v of' approximately .25" diameter and a metallic spool head1 extending.: approximately from the center of the magnetic core to the terminating edge da, the slot 5 is approximately 1/8 in length and .064 in width centered between the periphery of the core i and the edge ia of the metallic head 4.

The structure of the metallic head 4 is one of the determining factors respecting the time or operation of the electromagnetic devices. For example, in the form illustrated in Figs. -11 the metallic head 'I provides the slowest time constant of operation of all of the head structures, as the head 'I forms a substantially closed toroidal path for eddy currents. There is a small perforation 8 in the metallic head for purposes of keying the metallic head I to the insulation head t as heretofore explained. Figs. 12 and 13 are illustrative of the metallic head 4 heretofore discussed in Fig. 2 in which a time factor of operation, which is not as slow as the factor obtained with the structure of Figs. 1 0-ll, is secured. In Figs. 14--15 a metallic head 9 is illustrated having a radial slot l0 at one side thereof which serves to increase the speed factor of operation of the associated electromagnetic device by reducing the eddy current path. Figs. 16-17 illustrate the metallic end member il which is wholly slotted at I2 to provide the fastest operation for the associated electromagnetic devices of all of the structures illustrated, in that the eddy current path is wholly interrupted.

The insulation head 6, referred to in Fig. l., is illustrated more clearly in Figs. e9 and com-- prises two sheets of insulation material represented at Ill and I 5, arranged face to face and immediately adjacent the metallic head 4. The insulation head M. is provided with a projecting lug I5 which extends through the perforation 8, slot 5, slot IB or the slot I2 in any one of the forms of the metallic heads l, Il, 9 or II, respec tively, for keying the insulation head with respect to the metallic head. The insulation head ill serves as a support for the terminal members Il and i8, which are molded into the material of the insulation head I4. The terminal members I I and I8 each include segmental portions Ila and Ia which are perforated for the passage of the moldable material of the head I4 for keying the terminal members in position. The terminal members include solder lugs Illb and ISI) for effecting connection with the electromagnetic winding carried by the bobbin and terminal lugs I'Ic and |80 for establishing electrical connection between the external circuit and the winding car ried by the bobbin. The insulation head I5, which is assembled in abutment with the insulation head I4, is provided with grooves I9 and 2i) which are molded therein in directions which permit the electromagnetic winding to be started either in a clockwise or a counterclockwise direction.

In Fig. 6 I have illustrated in section the manner in which the projecting lug I0 extends through the slot 5 in the metallic head Ai from the head of insulation material i4. The insulation head I il is illustrated in immediate abutment with the head of insulation material ill. The insulation head i5, as heretofore described, contains the wire ways or grooves ifi and 20. A sheet of in sulation material 2l extends over the insulated head I5 and maintains the electrical conductors which are designated at 22 and 23 in position. A tubular member of insulation material 24?. extends over the magnetic core I and through the insulation sheet ZI to a position in abutment with the insulation head I 5.

The bobbin thus prepared is wound with the electrical conductor designated generally at 25 in Fig. 9 with the inner wire end thereof brought out through either groove I9 or 20 as designated by either reference character 22 or 23 in Fig, 8, depending upon the direction in which the winding of the bobbin is commenced. The end of the wire leading from the commencement of the winding and extending through either slot i9 or 20, is electrically connected and soldered to the lug Mib. The outside end of the electrical conductor is electrically connected and soldered to the opposite lug l'l'b. A tape, represented at 26, is wound over the winding. Upon completion of the winding of the bobbin, the electrical conductor is wound with a serving of cellulose acetate thread or other good insulating thread, such as, glass thread represented generally at 2li. The serving of th-read 2l is wrapped or wound over the layer of tape 2t and winding 25 and the bent lugs Ib and I 1b.

A coat of varnish or insulating compound is generally placed on the winding and over the tape 26 before serving with the thread 2l. Additional varnish is generally added while the thread 2l is being wound over the coil. The varnish or insulating compound may contain fungicide which will render the coil in its completed form fungusresistant. Bakelite varnish has been used to good advantage in this construction. After the serving is completed the coil is baked or dried thoroughly.

I have found that it is entirely practicable to produce a coil which will withstand approximately '700 hours or more in 95% humidity with positive current on the winding and negative current on the core, and after approximately 700 hours nd the resistance between the core and the winding to be not less than 20,000 megohms.

The opposite end of the coil support is formed in a manner similar to the coil support end heretofore described, and includes the disc-like end of insulation material represented at 23 backed by the metallic end 29. The metallic end 29 staked upon the end of the core l, as represented by the stake punchings 30 in Fig. 3, tending to expand the end of the core I to grip the metallic disc-like end 2S of the coil support.

The ability of the coil support of my invention to provide for the timing of the electrical operation of the `winding due to the controlled eddy current path resulting from variations in the structure of the metallic end shown in Figs. 10-1'7, is one of the outstanding advantages in the coilstructure of my invention. The maintenance of the insulated coil ends in spaced parallel planes, where the tendency for the insulation ends to curl or distort is a minimum, is another of the important advantages in the structure of my invention. The protection of the wire ends, the keying of the insulation end with respect to the metallic end, and the groove ing of the insulation end for the passage of the electrical conductor, all contribute to the advantages arising out of the structure of my invention.

' While I have described my invention in one of its preferred embodiments7 I realize that modifications may be made, and I desire that it be understood that no limitations upon my invenn tion are intended other than may be imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is as follows:

fl. A coil-supporting structure comprising a magnetic core, anv envelope of insulation mate. rial extending over said core, a. metaliic ami plate securedlto-said core, said. metallic end platefbeing perforated adjacent cneedge thereofV and a head of insulation material interposed between sai envelope and said metallic end plate, and: a pro.-J jection of insulation material extendingl from said head of insulation material disposed fromL said magnetic core and extending through. the perforation in said metallic end plate for keying said head of insulation' material with said metal.-v lic end plate.

2. A coil-supporting structure comprising a mag-netic core having a headed end, a metallic end plate disposed on said magnetic core and confinedI in abutting relationI withl said headed end, said metallic end platebeing perforated adjacent one edgel thereof a head of insulation material extending oversaid magnetic core and abutting against said metallic end plate, and a lug. of' insulation material projectingr from said head of insulation material' and extending through the perforation in said metallic endv plate for keying said insulated head with said metallic end plate.

3. A coil-supporting structure comprising a core having a headed end, a metal-liey end plate extending over said magnetic core andr abutting said headed end, said metallic end plate beingperforated adjacent one edge thereof a head of insulation material extending over said magneticcore, terminal members carried by said head of insulation material, a projection of insulation material on said head of insulation material extending in the direction of the headed end of said core through said metallic end plate, means carried by said magnetic core for insulatingly supporting a winding on said magnetic core, and insulation means disposed between said lastmentioned means and said insulated head.

4. A coil supporting structure comprising a magnetic core having a headed end, a metallic end plate abutting said headed end, said metallic end plate being perforated for controlling the circulation of eddy. currents through magnetic fields adjacent said plate, a head of insulation material extending over said magnetic core in abutting relation to said metallic end plate, said head of insulation material having a projection thereon extending in the direction of the headed end of said magnetic core and through the perforated end metallic plate for keying said head with said metallic end plate, terminals carried by said head of insulation material, means on said core for supporting a coil Winding thereon, and means interposed between said last-mentioned means and said head of insulation material for insulatingly separating the coil winding from said head of insulation material.

5. A coil-supporting structure comprising a magnetic core having a headed end, a metallic end plate extending over said magnetic core and abutting said headed end, said metallic end plate having a perforation therein for controlling the circulation of eddy currents in said metallic end plate, a head of insulation material extending over said magnetic core in abutting relation with said metallic end plate, said head of insulation material having a transversely extending tongue projecting in the direction of the headed end of said magnetic core through the perforated metallic end plate, terminal lugs imbedded in said head of insulation material, means for mounting coil winding on said magnetic core, and a sheet of insulation material extending between said last- 6? mentioned' means. and said head of insulation material.

6. A coil-supporting structure comprising a, magnetic core having a headed end thereon, ai metallic end plate extendingV over said` magnetic core in abutting relation to said metallic end plate, a head of; insulation material extendingr over said magnetic core in abutting relation tQ said metallic end plate, said; metali-ic endplate being perforated adjacent. oneA edge thereof' a projecting, lug of' insulation material integrally connected with said head of insulation materialand projecting in the direction of thehea-.dedend' of said magnetic core through the perforation in said metallic end plate, a coil winding carried: by' said magnetic core, and laminations of insulation material interposed between said coil winding and said: insulated head, one of the lamina-tions serv. ing as` a protector for the wire leads from Seid coil* winding and another of said lammations` servingas a separator between said coil wind; ing and said terminal lugs.

'7. A coil-supporting structure comprising a magnetic core having a headed end thereon, .a metallic and plate extending over said magneti-o core in abutting relation to said metallic endplate, said metallic endplate being perforated; adjacent one edge thereof a head of insulation material extending over said magnetic .core in abutting relation to s aid metallic end plate, a. projecting lug of insulation material integrally connected with said head, of insulation material and extendingv through the perforation in saidmetallic end plate, a coil. winding carried bysaid mag-netic core, and laminations of insulation, ma. terial' interposed between said coil winding and said head of insulation material, one of said laminations having angularly disposed grooves therein extending substantially tangentially to said magnetic core and terminating at the periphery thereof, and servingy as protective. chan-nel Ways for theA passage of leads from the inner portion of the coil windingv to one of saidl terminals and another of said laminations ex.- tending over the aforesaid lamination adjacent said coil winding for protecting the coil lead within the said groove.

8. A coil-supporting means comprising a magnetic core having a headed end, a metallic end plate extending over said magnetic core and abutting the headed end of said core, said metallic end plate being perforated adjacent one edge thereof a head of insulation material extending over said magnetic core and abutting said metallic end plate, a key member of insulation material integrally connected with said head of insulation material and projecting through the perforation in said metallic end plate, a coil winding carried by said magnetic core and having an inner lead extending therefrom, the head of insulation material having a pair of angularly disposed grooves in the face thereof extending substantially tangential to opposite points on said magnetic core for the passage of the inner lead from said coil winding, and terminal lugs carried by said head of insulation material for connection with the inner lead extending from said coil winding.

9. A coil-supporting means comprising a magnetic core having a headed end, a metallic end plate extending over said magnetic core and abutting the headed end of the core, said metallic end plate being perforated adjacent one edge thereof a head of insulation material extending over said magnetic core and abutting said metallic end plate, a key member of insulation material integrally connected with said head of insulation material and projecting through the perforation in said metallic end plate, and a coil winding carried by said magnetic core and having an inner lead extending therefrom, the head cf insulation material having a V-shaped groove re cessed into the face thereof adjacent said coil Winding with portions of the V-shaped groove extending substantially tangential to opposite points of said magnetic core for the passage of the inner lead from said coil Winding in the said V-shaped groove.

10. A coil-supporting means comprising a magnetic core having a headed end, a metallic end plate extending over said magnetic core and abutting the headed end of the core, said metallic end plate being perforated adjacent one edge thereof a head of insulation material extending over said magnetic core and abutting said metallic end plate, a key member of insulation material integrally connected with said head of insulation material and projecting through the perforation in said metallic end plate, a coil Winding carried by said magnetic core and having an inner lead extending therefrom, the head of insulation inaterial having a Vshaped groove recessed into the face thereof adjacent said coil Winding with portions of the V-shaped groove extending substantially tangential to opposite points of said magnetic core for the passage of the inner lead from said coil Winding in the said ll-shaped groove of said coil Winding, terminal lugs car-- ried by said head of insulation material, at ieast one of said terminal lugs being located adjacent said V-shaped groove for receiving and providing a terminal connection for the inner lead from said coil Winding, and a sheet of insulation Ina-- terial extending adjacent said coil Winding and serving to cover said V-shaped grooves for protecting the inner lead from said coil Winding.

11. A coil-supporting means comprising a magnetic core having a headed end, an electro* magnetic Winding carried by said core, a metallic end plate extending over said magnetic core and abutting the headed end of said core, said metallic end plate being perforated adjacent one side thereof for controlling the circulatory conductive path for eddy currents therein adjacent said magnetic core in the field of the electro-magnetic Winding carried by said core, and a head of inn sulation material disposed between the electromagnetic winding on said core and said metallic end plate, said head of insulation material having a key member of insulation material projecting normal therefrom and extending through the perforation in the metallic end plate.

12. In a coil-supporting structure a magnetic core having a headed end, a metallic end plate extending over said magnetic core and abutting the headed end of said core, said metallic end plate being perforated adjacent one edge thereof a head of insulation material extending over said magnetic core and abutting said metallic end plate, a key member of insulation material integrally connected with said head of insulation material and projecting through the perforation in said metallic end plate, and a pair of terminal members imbedded in said head of insulation material, each of said members including an arcuate-shaped portion having a connecting lug on one end and a connecting eyelet on the other end, said arcuate-'shaped portions being insulatingly spaced from each other through the insulation material of said headed end.

' OSBORNEv I. PRICE.

REFERENCES CITED The following references are of record in the fric of this patent:

UNITED STATES PATENTS Number Name Date 332,559 Robinson Dec. 15, 1885 936,669 Rypinski Oct. 12, 1909 1,616,207 *Wardell Feb. l, 1927 1,815,212 Ogg July 21, 1931 2,214,151 Wagar Sept. 10, 1940 

